Joseph a



(No Model.) 8

J. A. I. CRAIG.

DYNAMO ELECTRIC MACHINE.

"Il OMA illll!!!!!!l lllllllllm Patented May 8, 1883.

UNTTFD STATES PATENT OFFICF.

JOSEPH A. I. CRAIG, oF MONTREAL, QUEBEC, CANADA.

DYNAMo-ELECTRIC iviAci-ilNl-z.`

SPECIFICATION forming part ofALetters Patent No. 277,237, dated May 8, 1883.

Application filed September 7. i882. (No model.)

To all whom it may concern Beit known that I, JOSEPH A. I. CRAIG, ofthe city of Montreal, in the district ot' Montreal, and Province of Quebec, Canada, have invented certain new and useful Improvements in Dynamo-Electric Machines; and I do hereby declare that the following is a full, clear, and exact description ofthe same.

This invention relates to an improved construction and arrangementoflield-magnets ofa dynamo-electric machine, which may be brieiiy stated as consisting in a core of soft-iron wire wound in an elongated or other suitable form,

provided with elbows to preserve the shape of same, and separate or independent polar extensions, the said wire core being again covered with insulated wire wound transversely on the same.

The object of my invention is to increase the efficiency of the parts while working and allow the same to be readily put in place for operation or taken apart when requirechwhile greatly lessening the cost of the apparatus.

Many other advantages will accrue from the use of my invention, which will be apparent to those skilled in the art to which it pertains. For full comprehension ofthe same, reference must be had to the accompanying drawings, in which letters similar to those used in the following description indicate like parts, and where- Figure l is a side elevation ot a dynamoelectric machine, showing arrangement ot' my improved field-magnets. Fig. 2 is an end elevation ot' the same. Fig. 3 is a sectional elevation of the same, and Fig. 4 a detail view of sheet-metal plate or coresection used in the modified form of magnet.

Letter A represents the armature-shaft. Al represents in outline any suitable armature; F, the commutator, ot' whatever construction may be found most desirable, and B the framework supporting said parts, as shown, no claim being laid to any of these parts.

1n constructing the held-magnets for my dynamo-electric machine I do away with the solid iron core at present used and wind upon a suitable mold-hlock a sufiicient number of coils (represented by K) ot soft-iron wire, suitable elbows, Z lm on, being put in place at each corner or bend of the wire, as shown, for the purpose of keeping the wire coils K close together and in proper form. I generally construct these elbows Lm in two halves, the outer one of which is put on and secured over the wire after the same is wound. These elbows are constructed with flanges l m', and the ordinary insulated wire, u, is wound around the wire core K transversely, in the same manner as at present, thus forming helices N N O between the elbow-tlauges and thel polar exten` sions L M, which are of separate and inde pendent pieces of magnetic material, and arranged so as to nearly surround the revolving armature A. The wire core thus formed passes through grooves or recesses p in the polar extensions L M, and the helices are connected in any approved manner, as will be understood 'by electricians, a plate, P, being bolted down over said core, as shown, to hold the bundle ot wire together.

Q Q are plates, ot' brass or other suitable nou-magnetic material, extending across from one polar extension to the other, being bolted thereto, as shown, for the purpose of binding the same together, the insulation from the poles of the bolts or other devices for attaching saidplate thereto being accomplished in any approved way.

ln Fig. 4 I have shown a diagram ofa sheetmetal plate stamped in one piece to the conguration of the magnet and polar extensions, A2 indicating the space in which the armature revolves, and A3 A3 the polar extensions. A suitable number ot' these plates are placed together and the insulated wire wound round the same in the manner already described for Fig. 1, thus'forming a modication ofmy fieldmagnet, it being understood that these plates will take the place ot' the wires K, already alluded to as forming the core, and the separate cast polar extensions L M are done away with altogether; but I do not claim this modifica tion in the present application, reserving for myself the right of applying for a separate patent therefor.

By my invention I am enabled to construct a field-magnet in a very short time and for a small proportion of the cost necessary in the present arrangement, besides reducin g the cost ofthe other dependent parts of the dynamoelectric machine, as it will be apparent that much of the framing, Svc., can be donc away with.

ICO

Suitableline-connections,coinmntator-hrushes, driving-pulley, &c., will of course be necessary for the Working of my improved dynamoelectrie machine; but as these parts form no part of my invention and may be of any desired pattern, l have not thought it necessary to indicate or describe the saine.

I do not claim in the present application the `field-magnet made up of anumber of thin plates of metal piled together and wound with insulated wire, but reserve the right to make a separate application for a patent on the saine.

What I claim, and desire to secure by Letters Patent, is as follows:

In a dynamo-electric machine, the combina i 5 tion of a continuous` helix, K, ol iron wire, forming the core of the field-magnet, with separate polar extensions L M, each provided with a groove or 1'ecess,p, for the reception ot'I said core, elbows Z l on m, placed at the bends of said helical core 'for clamping the same, and magnet-coils N N O O, Wound over said core, all substantially as specified.

JOSEPH A. l. CRAIG.

Witnesses:

R. A. KELLOND, J. A. RENNIE. 

